openaire-library/utils/full-page-slider/full-page-slider.component.ts

import {AfterContentInit, Component, ContentChildren, Input, OnInit, QueryList} from "@angular/core";
import {SlideComponent} from "./slide.component";

@Component({
  selector: 'fp-slider',
  template: `
    <section (wheel)="onWheel($event)">
      <ng-content></ng-content>
    </section>`,
  styleUrls: ['full-page-slider.component.css']
})
export class FullPageSliderComponent implements AfterContentInit {
  
  @ContentChildren(SlideComponent) slides: QueryList<SlideComponent>;
  @Input()
  public initSlide = 1;
  public animate: boolean = false;
  public state = 0;
  
  ngAfterContentInit() {
    this.state = this.initSlide;
    this.setSlides(this.state);
  }
  
  setSlides(state = 1) {
    this.slides.forEach((slide, index) => {
      slide.state = state;
      slide.y = -50 + (index + 1)*200 - state*200;
    });
  }
  
  onWheel(event) {
    if (!this.animate) {
      this.animate = true;
      if (event.deltaY > 0 && (this.state < this.slides.length)) {
        this.state++;
        this.setSlides(this.state);
        setTimeout(() => {
          this.animate = false;
        }, 1000);
      } else if (event.deltaY < 0 && (this.state !== 1)) {
        this.state--;
        this.setSlides(this.state);
        setTimeout(() => {
          this.animate = false;
        }, 1000);
      } else {
        this.animate = false;
      }
    }
  }
}